Official Statistics

National Insurance Numbers stock categorisation

The full results of DWP's analysis and categorisation of all National Insurance numbers issued by DWP and its predecessor organisations.


National Insurance Number stock categorisation

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In 2007, DWP completed work to categorise the 76.8 million National Insurance numbers held on the DWP customer information system database for the UK.

Each number provides a unique numerical link between the individual and their National Insurance Contributions held on the HMRC National Insurance and Pay as you Earn Recording System. This was the most thorough and exhaustive analysis of these ever undertaken by DWP or any of its predecessor organisations.

Some of the analysis has since been used in answer to Parliamentary Questions and is therefore already in the public domain. In the interests of transparency, the full results are published here.

Published 19 July 2011